Articular cartilage has a poor intrinsic healing capacity that is likely related to the relatively low cellularity, metabolic activity, and avascularity of AC. Current clinical repair strategies for treating cartilage defects include tissue grafting and tissue engineering, yet there remains considerable debate about the best treatment strategy. The long-term goal of the research proposed here is to develop novel bioengineering analysis that may be used with experimental approaches to improve cartilage repair strategies. The objective of this proposal is to test the hypothesis that a cartilage growth mixture model employing a collagen network - fixed charge density stress balance can predict the evolution of biomechanical properties during in vitro growth protocols related to cartilage repair. Specifically, the first aim is to test if the evolution of strain-dependent biomechanical properties are related to biochemical parameters for several in vitro growth protocols of articular cartilage tissue. The second aim is to test if a cartilage growth mixture model with a collagen network - fixed charge density stress balance can be validated using experimental measures of biomechanical properties for several in vitro growth protocols of articular cartilage tissue. Important secondary aims of the proposed research are to enhance health related research in our predominantly undergraduate engineering program at Cal Poly, San Luis Obispo and to engage undergraduate students in biomedical research to help prepare them for careers in biomedical engineering.